The current phase of this project involves studies on the interactive effects of apomorphine, a putative activator of dopamine receptors, and olfactory impairment on mating, aggression, and stereotyped behavior in male golden hamsters. It has been found that apomorphine in low dosages greatly reduces the copulatory behavior but increases the aggression and stereotyped behavior of sexually active male hamsters. Future work will deal with the effects of olfactory impairment on the behavioral change produced by apomorphine. Also, the behavioral effects of other dopaminergic drugs will be tested. In particular, pimozide, a putative inhibitor of dopamine receptors, will be examined for its effects on normal hamsters and for its ability to block the behavioral effects of apomorphine.